Why is (Omkar) Om mantra called as pranav mantra?

All mantras originate from Om. It is a symbol of Brahman, God and the Vedas. Hence, the mantra ‘Om’ can bestow the Final Liberation (Moksha). This itself is the bija or the gist of the Vedas.

Why does a japa mala consist of 108 beads?

The japamala (rosary) usually consists of 108 beads in addition to the merubead. The four parts (charans) of each of the twenty-seven lunar asterisms (nakshatras) that is 27 x 4 equals one hundred and eight. These are represented by 108 beads in the mala.

How can one prevent other thoughts from occurring while chanting?

Just as sugar has sweetness as its quality, so also the nature of the mind is to think continuously or to harbour a certain emotion arising from some thought. In the beginning when chanting, everyone gets various thoughts due to the impressions from previous births.

Which Name should one chant if the Guru has not imparted a Name?

One should repeat (chant) the Name of the family deity (kuladevata), which refers to both the male or the female family deity. Depending upon which family deity’s worship is conducive for his spiritual progress, an individual is born in that particular family.

Namsankirtanyoga

Uniting the embodied soul with Supreme God through the medium of chanting the Name of the Deity is known as Namsankirtanyoga.